Shoulder/scapula

Question 1

Scapulohumeral (intrinsic shoulder) muscles

Answer 1

deltoid, supraspinatus, infraspinatus, teres minor, teres major, subscapularis

Question 2

Attachments of deltoid

Answer 2

Proximal: lateral third of clavicle, acromion and spine of scapula
Distal: deltoid tuberosity of humerus

Question 3

Innervation of deltoid

Answer 3

axillary nerve (C5, C6)

Question 4

Action of deltoid

Answer 4

anterior: flex and medially rotates arm
acromial (middle): abducts arm
posterior: extends and laterally rotates arm

Question 5

Attachments of supraspinatus

Answer 5

Proximal: supraspinous fossa of scapula
Distal: superior facet of greater tubercle of humerus (via strong flat tendon)

Question 6

Innervation of supraspinatus

Answer 6

suprascapular nerve (C5, C6)

Question 7

Action of supraspinatus

Answer 7

initiates (first 15 degrees) and assists deltoid in abduction of arm and acts with rotator cuff

Question 8

Attachments of infraspinatus

Answer 8

Proximal: infraspinous fossa of scapula
Distal: middle facet of greater tubercle of humerus

Question 9

Innervation of infraspinatus

Answer 9

suprascapular nerve (C5, C6)

Question 10

Action of infraspinatus

Answer 10

laterally rotates arm and helps hold humeral head in glenoid cavity of scapula, acting with rotator cuff

Question 11

Action of teres minor

Answer 11

laterally rotates arm and acts with rotator cuff

Question 12

Attachments of teres minor

Answer 12

Proximal: middle part of lateral border of scapula
Distal: inferior facet of greater tubercle of humerus

Question 13

Innervation of teres minor

Answer 13

axillary nerve (C5, C6)

Question 14

Attachments of teres major

Answer 14

Proximal: posterior surface of inferior angle of scapula
Distal: medial lip of intertubercular sulcus of humerus

Question 15

Innervation of teres major

Answer 15

lower subscapular nerve (C5, C6)

Question 16

Action of teres major

Answer 16

adducts and medially rotates arm at shoulder

Question 17

Attachments of subscapularis

Answer 17

Proximal: subscapular fossa
Distal: lesser tubercle of humerus

Question 18

Innervation of subscapularis

Answer 18

upper and lower subscapular nerves (C5, C6)

Question 19

Action of subscapularis

Answer 19

medially rotates arm, helps hold head of humerus in glenoid cavity (part of rotator cuff), adducts arm

Question 20

Rotator cuff muscles

Answer 20

SITS - supraspinatus, infraspinatus, teres minor, subscapularis

Question 21

Scapulohumeral muscles

Answer 21

deltoid
teres major
rotator cuff muscles (supraspinatus, infraspinatus, teres minor, subscapularis)

Question 22

Pectoral girdle joints

Answer 22

sternoclavicular (SC) joint
acromioclavicular (AC) joint
glenohumeral joint

Question 23

Sternoclavicular joint

Answer 23

saddle joint
ONLY bony attachment of upper extremity to axial skeleton
strong ligaments–>clavicle fractures before tear

Question 24

Acromioclavicular joint

Answer 24

plane joint
lesser mobility
site of shoulder separations

Question 25

Glenohumeral joint

Answer 25

ball-and-socket joint
MOST mobile joint in body
labrum and bursae!
no inferior reinforcement
site of shoulder dislocations (usually inferiorly)

Question 26

Site of shoulder dislocations

Answer 26

glenohumeral joint (usually inferiorly)

Question 27

Site of shoulder separations

Answer 27

acromioclavicular joint

Question 28

Blood supply of deltoid

Answer 28

posterior circumflex humeral artery (mostly, also: anterior circumflex humeral, deltoid branch of thoracoacromial, and profunda brachii)

Question 29

Blood supply of teres minor

Answer 29

lateral circumflex humeral artery + circumflex scapular artery

Question 30

Blood supply of teres major

Answer 30

thoracodorsal artery

Question 31

Blood supply of supraspinatus

Answer 31

suprascapular artery

Question 32

Blood supply of infraspinatus

Answer 32

suprascapular artery

Question 33

Blood supply of subscapularis

Answer 33

subscapular artery